CLIAMS:We claim:
1. A locking device to lock the slag dump car with the rails during dumping of the slag produced in steel making process from slag pot to slag dumping site wherein the locking device comprises-
- a holding means(13) welded to the body of the dump car to hold the lever mechanism(4) hinged to the lower part of the holding means
- a pair of guide blocks(2,3) attached to the said lever mechanism(4) to hold screw rod to keep the levers(4) in position
- a screw rod(1) having single start trapezoidal thread with left hand thread on one side and right hand side thread on another side engaged with the guide blocks(2,3) through the threaded holes provided in the guide blocks in conformity with the screw rod.
- a revolving means provided at the operator end of the screw rod (1)to rotate the screw rod enabling the movement of the guide blocks along with the cross levers attached to the guide blocks (2,3).
- Solid cross lever(6) & Split cross lever(5) attached to the lower portion of guide block wherein
the solid cross lever(6) is hinged to the lower part of guide block(3) in scissor arrangement with the split cross lever(5) hinged to lower part of other guide plate(2)

2. A locking device to lock the slag dump car with the rails, as claimed in claim 1 wherein, the holding means are brackets (13) welded to the body of the slag dump car with loaded slag pot in position.

3. A locking device to lock the slag dump car with the rails, as claimed in claim 1 wherein, the revolving means are a prefabricated steering handle (9).

4. A locking device to lock the slag dump car with the rails, as claimed in claim 1 wherein, the spacer (12) and nut (11) are provided opposite to operator end of the screw rod to arrest the accidental removal of the screw rod from the assembly by overturning of the steering wheel.

5. A locking device to lock the slag dump car with the rails, as claimed in claim 1 wherein, the levers(4) are kept in position by the trapezoidal thread screw rod (1) assembled to the guide blocks with right hand thread on one side and left hand thread on the other side.

6. A locking device to lock the slag dump car with the rails, as claimed in claim 1 wherein, the top and bottom ends of the split cross lever are joined by means of snap head rivets.

7. A locking device to lock the slag dump car with the rails, as claimed in claim 1 wherein, the hinged joints of inter connecting members are assembled by means of a pin (7), a washer (8) and split pin (10).

8. A locking device to lock the slag dump car with the rails, as claimed in claim 1 wherein, at least two such locking devices (L1, L2) are provided at the ends of the car on the dumping side.

9. A locking device to lock the slag dump car with the rails, as claimed in claim 1 wherein, the levers (5, 6) engages and disengages with the neck portion of the rail without foul with the top bulb portion of the rail (R) during the lock and unlock position.
,TagSPECI:Field of Invention

The present invention relates to a device for locking the slag dump car to the rail during the dumping of the slag from the slag pot. The slag dump car is locked to the rail by means of scissor configured lever arrangement. The scissor lever is operated by means of screw rod fixed with rotary wheel. The scissor lever locks the slag dump car to the rail by rotating the rotary wheel clockwise and unlocks by rotating anti-clock wise. The mechanism is designed for easy and ergonomic operation for locking the slag dump car.

Background of the invention

In the steel industry slag is produced as a by-product. Millions of tonnes of slag are produced by converters, electric furnaces. The great challenge is to transport this slag safely, quickly and efficiently. This slag should be transported to the slag dumping area to keep operations running in the steel making process and to keep premises clean and available for further works.

The slag pot is placed on a slag dump car, which is tilted to one side to empty its contents and in tilting, travels from a vertical position to a full dump position. The movement of the slag dump car as well as tilting of slag pot is controlled form a control post. The tilting of the slag pot is carried out by rack and pinion mechanism. Once the slag pot is tilted, centre of gravity moves away from the axis of the slag dump car. In order to prevent the toppling of the slag dump car due to shift in the centre of gravity of the car, it is locked to the rails by means of lever chain.

These slag pots are large and heavy and have carrying capacities of 100 Metric Tonnes and more. The angle of tilt while dumping the slag from the slag pot is about 120°.

Slag transporters are required that can be adapted perfectly to the conditions prevailing in the area of slag transportation, which are tough on men and machines, such as temperatures up to 1,600° C and high payloads. Various means in use for dumping of slag by conventional methods are not economical and lack safety aspects.

Liquid slag of each basic oxygen converter will be poured into the slag pot 16/18 meter cube capacity placed on a self propelled slag pot transfer car running below the converter. The slag pot transfer car transports the slag pot to the slag yard. The slag pot is lifted from the transfer car by the EOT cranes and will be placed on the self propelled slag dump car. The slag dump car operates on rails laid at the ground level along the slag pit with tilting mechanism for dumping the slag into the pits.

The operation of locking the slag dump car to the rail requires bending and lifting the lever by the operator. After dumping the slag, the pot is restored to vertical position by reversing the drive direction from the same control post and the car itself is propelled back to the slag yard where the empty slag pot is lifted by the EOT crane and placed on the transfer car for carrying back the pot.

The car should be locked at two locations to the rail on the non dumping side of the car. After completion of the slag dumping the slag dump car need to release from rail lock for further operation. The lever chain which weights around 20 Kgs need to be manually lifted and locked to the rail before dumping and subsequently unlocked for the free movement of the slag dump car after dumping.

Object of the invention
The invention relates to the ergonomic locking of slag dump car with the rail during the dumping of the slag from the slag pot. The ergonomic locking arrangement is designed suiting the site conditions, by taking into considerations the slag dump car operation and approach constraint for locking it. The slag dump car is locked to the rail by means of lever arrangement. The scissor lever is operated by means of screw rod fixed with rotary wheel. The scissor lever locks the slag dump car to the rail by rotating the rotary wheel clockwise and unlocks by counter clock wise rotation. The mechanism is designed for easy and ergonomic operation for locking the slag dump car. The mechanism has been successfully implemented in the slag dump car.

According to present invention, a locking device is meant for locking the slag dump car with the rails during dumping of the slag, produced in steel making process from slag pot to slag dumping site. The locking device comprising the brackets welded to the body of the dump car to hold the lever hinged to the lower part of the brackets. The brackets are welded in loaded slag pot in position to ensure the exact location of weld on the slag dump car. A pair of guide blocks attached to the said lever to hold screw rod to keep the levers in position.

According to an embodiment of the present invention a screw rod having single start trapezoidal thread with left hand thread on one side and right hand side thread on another side engaged with the guide blocks through the threaded holes provided in the guide blocks in conformity with the screw rod.
A revolving means is provided at the operator end of the screw rod to rotate the screw rod enabling the movement of the guide plates along with the cross levers attached to the guide blocks. This revolving means can be a pre fabricated steering wheel or other analogous structure. On the other end i.e. opposite to operator end a spacer and a nut are provided to check the accidental removal of the screw rod from the assembly by overturning of the steering wheel.

According to further embodiment, Solid cross lever & Split cross lever are attached to the lower portion of guide plate. They are joined in such way that the solid cross lever is hinged to the lower part of guide plate and is in scissor arrangement with the split cross lever hinged to lower part of other guide plate.
The top and bottom ends of the split cross lever are joined by means of snap head rivets. All the hinged joints of inter connecting members are assembled by means of a pin, a washer and split pin. The Solid cross lever & Split cross lever engages and disengages with the neck portion of the rail without foul with the top bulb portion of the rail during the lock and unlock position.

According to further embodiment at least two such locking devices are provided at the ends of the car on the non dumping side to make effective locking of the dump car. The dump car is locked on non dumping side of the car to protect the car from toppling during the dumping of the slag from the slag pot.

Detailed Description

The present invention describes the general arrangement of anchoring of the slag dump car to the rails. A screw rod with single start trapezoidal thread with LH on one side and RH on another side is provided. This screw rod is engaged with the guide blocks having threaded holes in conformity with the screw rod to hold screw rod in position. The levers are hinged to the guide block at lower end, while upper end of the lever is hinged to the bracket welded to the body of the slag dump car. The brackets are w¬elded to the slag dump car with loaded slag pot in position. This ensures the exact location of weld on the slag dump car. The split cross levers are hinged to the lower end of the guide block. The split cross levers are joined at the top and bottom ends by means of snap head rivets. The solid cross lever are hinged to the lower part of another guide block. This cross lever is assembled into the split cross lever making a scissor arrangement. The split cross lever and solid cross lever are also hinged through a fulcrum. Towards the operator end of the screw rod a pre fabricated steering handle is fixed and locked by means of a hexagonal Nut. The other end of the screw rod is fixed with spacer and a hexagonal Nut. This arrangement prevents the accidental removal of the screw rod in assembly by overturning the steering wheel. All the hinged joints of inter connecting members are assembled by means of pin, washer and split pin. The anchoring mechanism is tested for its smooth operation before thorough welding.

The turning wheel is placed at 450 mm from the ground level for easy access of the operator without bending. The anchoring mechanism need to be operated before tilting and after tilting of the slag pot by the slag dump car. Two such anchoring mechanisms are to be welded to the ends of the car on the non dumping side.

The free end of solid cross lever and the split cross lever is shaped to match the rail and the shape of the lever is designed is such a way that the lever engages and disengages with the neck portion of the rail without foul with the top bulb portion of the rail during the lock and unlock position. The height of the operating wheel is chosen to be in the convenience range of the operator. The levers are kept in position by the trapezoidal thread screw rod assembled to the guide block with right hand thread on one side and left hand thread on the other side.

Considering the forces acting on the lever about the fulcrum ,
Ra x L1 = Fa sina x L1,
Rb x L2 = Fb sina xL2.
Fc = Fa sin a,
Fd = Fb sin a,
Allowable shear load of the fulcrum pin = 250 x n x 502 /4 = 490873.8 N= 490KN.

Allowable shear load of the lever = 250 x 40 x 50 = 50,000 N= 50 KN.
Assuming Fc = Fd, Ra = Rb = 25x175/261 = 16.76 KN.
The locking device can be easily operated for locking and unlocking the slag dump car by turning the drive wheel clock wise and counter clock wise direction respectively. It is a safe and ergonomic design as the operation of lifting the weight by bending of the operator for locking and unlocking the slag dumping car during its process has totally been eliminated.

The present technique is further described hereinafter with reference to the accompanying drawings, wherein

Fig 1: is showing the locking device in unlocked position
Fig 2: is showing the locking device in locked position with rails.
Fig 3: is a schematic view of the different parts and forces acting thereon as described above.
Fig 4: is showing general arrangement of the anchoring on the slag dump car.

Figure1 is showing the different component of the locking device. The brackets (13) are welded to the body of dump car. Levers (4) hinged to the brackets as shown. The lower end of the levers (4) is hinged to the guide blocks (2, 3) on their respective side. A threaded screw rod (1) is engaged with the guide blocks (2,3) having threaded holes in conformity with the screw rod to hold screw rod (1) in position. A steering handle (9) is provided at operator end of the screw rod to turn the screw rod to facilitate the locking. This steering handle is locked to the screw rod with a hexagonal nut (11). On the other end of the screw rod a spacer (12) and a hexagonal nut (11) is provided to keep the screw rod in assembly and prevent the accidental removal of the screw rod by overturning the steering.

A split cross lever (5) is hinged at the lower portion the guide block (2). A solid cross lever (6) is hinged to the lower portion of another guide block (3) making scissor arrangement through a fulcrum (14). These cross levers (5, 6) engages and disengages with the rail (R) to lock and unlock the dump car.

Fig 2, shows the locking device in an unlocked position with rails. The Solid cross lever (6) & Split cross lever (5) engages with the neck portion of the rail (R) without foul with the top bulb portion of the rail during the lock position.

Fig 3 shows the different forces acting on the lever about the fulcrum(14). The locking device can be easily operated for locking and unlocking the slag dump car by turning the drive wheel clock wise and counter clock wise direction respectively.

Fig 4, shows the general arrangement of the anchoring on the slag dump car. At the least two locking devices (L1, L2) are provided at the ends of the car on the non dumping side to make effective locking of the dump car. Fig 3a is the front elevation of the dump car along with the locking device while Fig 3b depicts the top view of the dump car along with the locking device.

The above description of the exemplary embodiments according to the present invention serves only for illustration purposes and not to restrict the invention. Various changes and modifications are possible within the context of the invention, without departing from the scope of the invention and its equivalents.